Next.js Daily: React Upgrade and Cache Handler Fixes

Transcript

Good morning. This is Next.js Daily for March 31st, 2026.

The Next.js team upgraded React from build 9627b5a1 to 74568e86, updating 82 files with upstream changes from React pull request 36156. Vedant Madane merged a fix for handling file:// URLs from import.meta.resolve in cache handler paths, resolving issue 73796 where ESM projects couldn't properly use import.meta.resolve for cache handlers due to invalid path concatenation.

Will Binns-Smith added experimental.serverFastRefresh to next.config.js, allowing users and plugins to disable server-side fast refresh programmatically rather than through CLI flags. The same contributor also fixed metadata route hot reloading in Turbopack by excluding them from server HMR, ensuring changes to manifest.ts, robots.txt, and similar files reflect immediately.

Hendrik Liebau reverted a Turbopack change for hash-based change detection that was causing filesystem cache test failures, then merged improvements to varyParams tracking for cached navigations to better handle fallback parameters. Sebastian Silbermann updated route type generation to include debugging information about which files caused specific route types.

The team moved expanded adapter documentation from the config section to a dedicated API reference section, making the information more accessible. Aurora Scharff clarified that the "use cache" directive requires async functions at all levels, not just file level. Additional fixes included Windows path parsing improvements in Turbopack and CI workflow adjustments for adapter test result uploads.

What's next: Watch for continued React integration improvements and Turbopack stability enhancements. The server fast refresh configuration option should help plugin developers manage compatibility issues.

That's your Next.js Daily update. We'll be back tomorrow with more framework developments.